Alternating HP and FMJ Causing Jams. Why?

[Timothy Bryant]

Hello all! I have a RIA 1911 Tactical 45 and am very pleased with the firearm for the most part but have noticed noticed something very peculiar (to me at least) and was wondering if anybody could offer up some kind of explanation. Recently I had two boxes of ammo, one WWB Hollowpoints and the other Federal Champion FMJ, and whenever loading an entire mag with the same bullet type the gun cycles perfectly. Oddly though if I stagger the ammunition FMJ/HP in the mag it causes jam's consistently. The kind of jam I'm getting is odd. It seems as though the round is chamber fully but the slide fails to fully return to battery and I must lock the slide open while I forcibly remove the freshly loaded and unfired round. Does anybody out there have any sort of explanation as to why this may be occurring?

 

[Warbirds]

You rang the dinner bell on a touchy subject. There has been a lot of discussion on alternating ammo types in a defensive handgun. I have no experience or even a guess, and i don't know if you are going to get much helpful advice.

Sent from my SPH-L710 using Tapatalk 2

 

[Purple]

I can see no reason to alternate defensive ammo in your carry. Shoot one or the other, which means the one you select is all you carry in your mags and gun. There are several reason why your gun won't cycle correctly when alternating ammo, but it doesn't matter if you follow the main rule of thumb with your defensive carry - only carry ammo that cycles 100% of the time.

 

[walt629]

Check the feed ramp. Is it smooth? Check the length of the bullets compared to each other and how they sit in the stack. Are the rims of the cases stacking evenly and is each round sitting firmly against the rear of the magazine? Possibly, If the round under the one being stripped is sitting a bit forward of the one being stripped, the rim of the case being stripped could momentarily catch on the round below it and force the nose of the round against the front of the magazine, causing a momentary snag that will slow down the magazine from inserting the top round fully.

Com[are th eoverall bullet length between the round you want to shoot. THere needs to be no difference between them.

Next time you want to run a mixed magazine try the "tap". After loading the magazine, smack the rear of the magazine into your palm to get all the loads to settel to the rear of the magazine stack.

 

[Timothy Bryant]

It really isn't a big deal for me that the gun will not cycle a mixed magazine of ammunition as I only intend to carry one type of bullet in it at a time but I alternated them just on whim to see if it'd cycle properly and it didn't. Now I know I shouldn't worry about it so long as it will cycle a full magazine of whichever ONE type I choose but it does something to me mentally to know that, if mixed, I am very likely to experience a jam. I guess an explanation of some sort would just ease any concerns I have relative to the jams.

Thanks for the tips Walt. I always perform the "tap" you described after loading either of my magazines and if it helps or not I'm not sure but it's become habitual. As far as your tip about compare the overall lengths, I have noticed that the shell casing seems just a bit longer of the FMJ than the HP and the HP also appears shorter due to the truncated and hollow projectile. Perhaps this could be leading to the jams.

 

[etazelaar]

I'm very interested in figuring this out myself. I've been handloading for a few years now just became a gunsmith. Are all the cases nickel plated or brass? Is the ogive, the curve of the front of the bullet, the same? Do the manufacturers state the same velocity? I hope you find the answer and post it.

 

[Purple]

I'm very interested in figuring this out myself. I've been handloading for a few years now just became a gunsmith. Are all the cases nickel plated or brass? Is the ogive, the curve of the front of the bullet, the same? Do the manufacturers state the same velocity? I hope you find the answer and post it.

You've hit most of the issues in your post. Ammo is usually the cause for gun cycle issues, and rarely is it truly just the gun. Some factors with ammo include bullet type, case/bullet length, bullet weight, round charge (pressure and velocity), primer depth in case, case base thickness, and case material (brass, nickle, aluminum, steel).

Gun issues include feed ramp angle and polish, recoil/buffer spring tension, tight tolerances between the slide and frame, fire control group fit and hammer tension, firing pin spring tension and length, magazine, etc.

Shooter issues are also common. Limp wrists and a persons grip can adversely effect handgun performance.